Rotary encoders are frequently used to determine the angular position of two machine parts, which are rotatable relative to each other, and operate according to an inductive measuring principle, for example. In inductive rotary encoders, exciter coils and receiver coils are applied, for example, in the form of circuit traces, on a shared circuit board, which is permanently joined to a stator of the rotary encoder, for example. Arranged across from this circuit board at a defined axial distance and centered is another board, which takes the form of a code disk, on which alternating electrically conductive and non-conductive surfaces are mounted at periodic intervals as a scale-division region or scale-division structure, and which is joined to the rotor of the rotary encoder in a rotatably fixed manner. If an electric exciter field, which is alternating over time, is applied to the exciter coils, then signals are generated in the receiver coils as a function of the angular position during the relative rotation between rotor and stator. These signals are processed further in an evaluation electronics.
Such rotary encoders are frequently used as measuring devices for electrical drives to determine the absolute angular position of respective drive shafts.
European Patent No. 0 973 014 describes an arrangement for a rotary encoder, in which the axial distance between a detector system and a code disk is locked by a bow-shaped element, which clamps a rotary encoder shaft in a form-locking manner by a radial longitudinal displacement. Such devices have the disadvantage, among other things, that they require for their actuation a comparatively large amount of space in the radial direction.